Recently, a visible light communication system (a visible light ID system) is known, which is configured to modulate visible light (illumination light) emitted from a lighting apparatus (a transmitter) to transmit unique ID information and the like to the lighting apparatus, and demodulate the ID information with a receiver (a receiving terminal) configured to receive the visible light (see JP 2009-206620 A, hereinafter referred to as “document 1”).
In the conventional example described in the document 1, the visible light communication system includes a server. The server stores translation data table, which translates identification information of the lighting apparatus into positional information of the lighting apparatus, and additional information, which is correlated with the positional information. That is, when receiving the identification information from a prescribed lighting apparatus, the receiving terminal acquires in a lump, from the server, translation data table, which corresponds to a set area relating to the prescribed lighting apparatus, and additional information. Furthermore, when receiving the identification information from a lighting apparatus in the set area, the receiving terminal refers to the translation data table and then outputs positional information and additional information corresponding to the identification information.
By the way, the conventional visible light communication system described in the document 1 or the like has a problem described below about security.
That is, a security measure such as encryption is not often performed for ID information transmitted from the lighting apparatus through the visible light communication. Therefore, content thereof may be easily known to a third party. Accordingly, a person trying to misbehave can access to the server and acquire various information (the positional information or other service information) corresponding to the ID information without acquiring the ID information from the lighting apparatus.